Extreme color variations during print run

[Tomiyama]

I'm trying to print fine greeting cards on a Canon Pixma iX6820, working from a color-corrected Photoshop file. If I print the cards one at a time, the color is fine. If I set the printer to print two cards, the color of the second one will be appallingly off -- purple instead of red, etc.

I have checked ink supply, run test print, downloaded new printer driver and all the usual stuff. Has anyone else encountered this problem?

[Patrick]

Hi Tomiyama,

Please open the cover to your iX6820.  From left to right, what is all of the text on each ink tank that is installed in your printer?

In regards to the test page that you printed, does it match the image below: